At-most-once delivery in Kafka - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the producer to at-most-once delivery by disabling retries.

Kafka

props.put("retries", [1]);

Drag options to blanks, or click blank then click option'

A5

B0

C-1

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Setting retries to a positive number causes retries, which is not at-most-once.

Using -1 enables infinite retries, which is not at-most-once.

Setting retries to 0 disables retry attempts, ensuring at-most-once delivery.

2fill in blank

medium

Complete the code to disable idempotence for at-most-once delivery.

Kafka

props.put("enable.idempotence", [1]);

Drag options to blanks, or click blank then click option'

Afalse

Btrue

C"true"

D"false"

Attempts:

3 left

💡 Hint

Common Mistakes

Setting idempotence to true enables exactly-once semantics, not at-most-once.

Using string values instead of boolean can cause configuration errors.

Disabling idempotence by setting enable.idempotence to false allows at-most-once delivery.

3fill in blank

hard

Fix the error in the producer configuration to ensure at-most-once delivery by setting the acks correctly.

Kafka

props.put("acks", [1]);

Drag options to blanks, or click blank then click option'

A"0"

B"-1"

C"1"

D"all"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "all" or "-1" waits for all replicas, which is not at-most-once.

Using "1" waits for leader acknowledgment, which can cause retries.

Setting acks to "0" means the producer does not wait for any acknowledgment, enabling at-most-once delivery.

4fill in blank

hard

Fill both blanks to create a producer config map for at-most-once delivery with no retries and no idempotence.

Kafka

Map<String, Object> props = new HashMap<>();
props.put("retries", [1]);
props.put("enable.idempotence", [2]);

Drag options to blanks, or click blank then click option'

A0

Btrue

Cfalse

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Setting retries to 1 or more enables retries, breaking at-most-once.

Setting idempotence to true enables exactly-once semantics.

Retries set to 0 disables retries, and idempotence set to false disables duplicate prevention, both needed for at-most-once delivery.

5fill in blank

hard

Fill all three blanks to configure a Kafka producer for at-most-once delivery: no retries, no idempotence, and no acknowledgments.

Kafka

props.put("retries", [1]);
props.put("enable.idempotence", [2]);
props.put("acks", [3]);

Drag options to blanks, or click blank then click option'

A1

Bfalse

C"0"

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using string "0" for retries instead of integer 0 causes errors.

Setting idempotence to true enables exactly-once semantics.

Setting acks to "1" or "all" waits for acknowledgments, not at-most-once.

Retries set to 0 disables retries, idempotence false disables duplicate prevention, and acks "0" disables waiting for acknowledgments, all together ensuring at-most-once delivery.